Slow Upload/Deploy for Windows 7 64-bit to 160GB Hard Drives

I’ve recently upgraded my Windows 7 32-bit machines to 64-bit and have been experiencing slowness with deploys and uploads using FOG 0.32. I’ve observed that my Win7 64-bit image (~31GB) deploys via unicast normally at around 2.5-3.0 GB/min to an HP desktop with a 160GB Seagate hard drive until it reaches ~60%. From there the speed drops to under 1 GB/min and takes an additional 35 mins to complete. This is the same behavior for uploads and multicasts.

I’ve tried different Win7 64-bit images, other desktops of the same model and hard drive, and different networking gear which results in the same issue. However, pushing out a Win7 32-bit (~21GB) image to the same machine takes only 6 minutes with no issues.

I tried replacing the current hard drive (Seagate SATA/300 7200RPM 160GB) with a larger 250GB hard drive (SATA/300 7200RPM) and the deploy performed without any slow downs or issues.

I’m trying to find a solution without having to replace all my 160GB hard drives and I don’t quite understand why the 32-bit image works while the 64-bit image has issues when deploying to the same machine. Are there known issues with FOG performance and hard drive models? Or with Windows 7 64-bit vs 32-bit images and FOG and/or hard drives?